Flywheel Device of Bicycle

ABSTRACT

Disclosed is a flywheel device of a bicycle, including a flywheel means, a clutching means and a speed transforming means. The flywheel means is installed in rotation with the frame that is placed between the driving wheel and the driven wheel. The clutching means is engaged or disengaged between the flywheel means and the driving wheel according to an engaging state and a disengaging state thereof, wherein, a rotational energy is transferable between the flywheel means and the driving wheel during in the engaging state. The speed transforming means is connected between the flywheel means and the driving wheel by means of the clutching means to adjust a transmission ratio in relation to the driving wheel and the flywheel means.

FIELD OF THE INVENTION

The present invention relates to an assist device of a bicycle, and more particularly to a flywheel device of a bicycle.

BACKGROUND OF THE INVENTION

A bicycle is widely popular to people all around the world. The movement of the bicycle is driven depending on a pedaling force or a resistance force applied by a rider.

A rider can save an applying pedaling force either by an inertia generated from the bicycle and the rider itself in a movement or by a slope degree of a road. However, once the bicycle is slowed down or is stopped while it is in an uphill, in a situation against the wind, or in an emergency, the rider will have to take much effort to pedal the bicycle again to gain the original speed.

Further, when a bicycle is slowed down or is to stop, the bicycle will be unsteady to loss of balance to cause the rider falling down or being hurt.

SUMMARY OF THE INVENTION

In view of above, the bicycle of a prior art has a defects that a rider needs to take a great effort to pedal the bicycle to start or to speed up, and tends to loss the balance while the bicycle is slowed down or is to be stopped.

Accordingly, it is an object of the present invention to provide a flywheel device of a bicycle that provides the assist for speeding up and slowing down, and maintains the balancing of the bicycle.

The present invention provides a flywheel device of a bicycle, the bicycle having a frame, a driving wheel and a driven wheel, the flywheel device comprises: a flywheel means installed on the frame that is placed between the driving wheel and the driven wheel, a rotation axis of the flywheel means being substantially parallel to a rotating axis of the driving wheel; a clutching means, engaged or disengaged between the flywheel means and the driving wheel according to an engaging state and a disengaging state thereof, wherein, a rotational energy is transferable between the flywheel means and the driving wheel during in the engaging state; and a speed transforming means connected between the flywheel means and the driving wheel by means of the clutching means to adjust a transmission ratio in relation to the driving wheel and the flywheel means.

According to an embodiment of the present invention, the driving wheel is a rear wheel of the bicycle.

According to an embodiment of the present invention, the flywheel means is positioned between a down tube and a seat tube of the frame.

According to an embodiment of the present invention, the flywheel means has a flywheel edge partly extending beyond a top tube of the frame.

According to an embodiment of the present invention, the flywheel means is rotated in connection with the driving wheel via a transmission member.

According to an embodiment of the present invention, the clutching means is provided with a handling member for shifting the clutching means in the engaging state or the disengaging state.

According to an embodiment of the present invention, the speed transforming means includes an input transforming assembly and an output transforming assembly, the input transforming assembly is provided to adjust an input transmission ratio of the driving wheel to the flywheel means, and the output transforming assembly is provided to adjust an output transmission ratio of the flywheel means to the driving wheel.

According to an embodiment of the present invention, the input transmission ratio of the driving wheel to the flywheel means is adjusted as an acceleration transmission ratio by the input transforming assembly.

According to an embodiment of the present invention, the output transmission ratio of the flywheel means to the driving wheel is adjusted as an acceleration transmission ratio by the output transforming assembly.

According to an embodiment of the present invention, the flywheel device further comprises a ratchet means, assembled between the flywheel means and the driving wheel via the speed transforming means.

By means of technical means of the present invention, the flywheel device according to the present invention can selectively store and release a rotational kinetic energy in a way that the bicycle is starting, speeding up, slowing down and stopping easier to save rider's effort on riding. Further, the flywheel device according to the present invention stores the rotational kinetic energy by means of rotating manner, so an angular momentum of the rotation can be helpful for balancing the bicycle.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings.

FIG. 1 is a side view of a flywheel device according to an embodiment of the present invention;

FIG. 2 a is a top view of the flywheel device according to the embodiment of the present invention when the bicycle is slowing down;

FIG. 2 b is a top view of the flywheel device according to the embodiment of the present invention when the bicycle is stopping; and

FIG. 2 c is a top view of the flywheel device according to the embodiment of the present invention when the bicycle is speeding up.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described hereafter with reference to FIGS. 1 to 2 c. The present invention, however, should not be construed as limited to the embodiment set forth herein. These embodiments should be considered as only the examples of the present invention.

As shown in FIG. 1, a flywheel device 2 according to an embodiment of the present invention is allocated on a bicycle 1 that has a frame 11, a driving wheel 12 and a driven wheel 13. The flywheel device 2 includes: a flywheel means 21 installed on the frame 11 that is placed between the driving wheel 12 and the driven wheel 13, a rotation axis 210 of the flywheel means 21 being substantially parallel to a rotating axis 120 of the driving wheel 12; a clutching means 22, engaged or disengaged between the flywheel means 21 and the driving wheel 12 according to an engaging state and a disengaging state thereof, wherein, a rotational energy is transferable between the flywheel means 21 and the driving wheel 12 during in the engaging state; and a speed transforming means 23 connected between the flywheel means 21 and the driving wheel 12 by means of the clutching means 22 to adjust a transmission ratio in relation to the driving wheel 12 and the flywheel means 21.

In the flywheel device 2 according to the embodiment of the present as shown in FIG. 1, the driving wheel 12 is rotated by a rider who pedals a pedal 14 of the bicycle 1. In detail, a rotation energy generated by pedaling the pedal 14 is transferred through a chain ring 15 and a chain 16 to the driving wheel 12 to thus drive the bicycle 1 for moving forward. However, the present invention is not limited to this, and in another embodiment, the rotation energy may be transferred to the driving wheel 12 through other transferring means other than the chain ring 15 and the chain 16.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIG. 1, the driving wheel 12 is a rear wheel of the bicycle 1. However, in another embodiment, the driving wheel 12 may be a front wheel of the bicycle 1 or a wheel in any other position of the bicycle 1.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIG. 1, the flywheel means 21 is positioned between a down tube 111 and a seat tube 112 of the frame 11. In such arrangement, the center of gravity of an integral bicycle 1 and the flywheel device 2 will be maintained on the frame 11 as between the front and rear wheels for balancing the bicycle 1 and preventing the bicycle 1 from being turned over.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIG. 1, the flywheel means 21 has a flywheel edge 211 that is mostly extending beyond a top tube 113 of the frame 11. The larger radius of the flywheel means 12 is, the larger moment of inertia will be obtained, so the rotation will generate a larger angular momentum. Accordingly, the flywheel means 21 having a larger radius can improve the balancing of the bicycle 1.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIG. 1, the flywheel means 21 is rotated in connection with the driving wheel 12 via a transmission member. The transmission member, such as a chain or a belt, is connected between the flywheel means 21 and the driving wheel 12 to enable the flywheel means 21 and the driving wheel 12 to rotate with each other. However, in another embodiment, the flywheel means 21 may be rotated in connection with the driving wheel 12 via other means, such as a gear set.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIG. 1, the clutching means 22 is provided with a handling member 223, which is installed on handlebar 17 for shifting the clutching means 22 in the engaging state or the disengaging state. However, the handling member 223 is not limited to be installed on the handlebar 17, and the handling member 223 may be installed on any position or may be operated by, for example, feet.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIGS. 2 a, 2 b and 2 c, the speed transforming means 23 includes an input transforming assembly 231 and an output transforming assembly 232. The input transforming assembly 231 is for adjusting an input transmission ratio of the driving wheel 12 to the flywheel means 21, and the output transforming assembly 232 is for adjusting an output transmission ratio of the flywheel means 21 to the driving wheel 12. Correspondingly, the clutching means 22 includes a first clutching assembly 221 and a second clutching assembly 222. The first clutching assembly 221 selectively enables the connection between the flywheel means 21 and the driving wheel 12 by means of the input transforming assembly 231 of the speed transforming means 23, and the second clutching assembly 222 selectively enables the connection between the flywheel means 21 and the driving wheel 12 by means of the output transforming assembly 232 of the speed transforming means 23.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIG. 2 a, the input transmission ratio of the driving wheel 12 to the flywheel means 21 is adjusted as an acceleration transmission ratio by means of the input transforming assembly 231. Specifically, the input transforming assembly 231 includes a first input chain ring 231 a connected with the driving wheel 12, a second input chain ring 231 b connected with the flywheel means 21, and an input chain 231 c connected between the first input chain ring 231 a and the second input chain ring 231 b. Since the teeth number of the first input chain ring 231 a is larger than that of the second input chain ring 231 b, when the driving wheel 12 is connected with the flywheel means 21 via the input transforming assembly 231, the driving wheel 12 can drive the flywheel means 21 through the first input chain ring 231 a, the input chain 231 c and the second input chain ring 231 b to rotate in a manner that the rotation speed of the flywheel means 21 is faster than that of the driving wheel 12 based on the acceleration transmission ratio.

In the flywheel device 2 according to the embodiment of the present invention as shown in FIG. 2 c, the output transmission ratio of the flywheel means 21 to the driving wheel 12 is adjusted as an acceleration transmission ratio by means of the output transforming assembly 232. Similarly, the output transforming assembly 232 includes a first output chain ring 231 a connected with the flywheel means 21, a second output chain ring 232 b connected with the driving wheel 12, and an output chain 232 c connected between the first output chain ring 232 a and the second output chain ring 232 b. Since the teeth number of the first output chain ring 232 a is larger than that of the second output chain ring 232 b, when the driving wheel 12 is connected with the flywheel means 21 via the output transforming assembly 232, the flywheel means 21 can drive the driving wheel 12 through the first output chain ring 232 a, the output chain 232 c, and the second output chain ring 232 b to rotate in a manner that the rotation speed of the driving wheel 12 is faster than that of the flywheel means 21 based on the acceleration transmission ratio.

As shown in FIGS. 2 a, 2 b and 2 c, the flywheel device 2 according to the embodiment of the present invention further includes a ratchet means 24, which is assembled between the flywheel means 21 and the driving wheel 12 via the speed transforming means 23. The ratchet means 24 is a mechanical means that forces a rotation moving in a single direction so as to prevent any rotation in its opposite direction to thus keep a single direction transmission between the flywheel means 21 and the driving wheel 12. Corresponding to the speed transforming means 23, the ratchet means 24 includes an input ratchet 241 and an output ratchet 242. The input ratchet 241, which is assembled between the flywheel means 21 and the driving wheel 12 via the input transforming assembly 231, maintains the energy being transferred from the driving wheel 12 to flywheel means 21, and prevents the energy from being transferred from flywheel means 21 back to the driving wheel 12 while the rotation speed of the driving wheel 12 is slower than that of the flywheel means 21. Similarly, the output ratchet 242, which is assembled between the flywheel means 21 and the driving wheel 12 via the output transforming assembly 232, maintains the energy being transferred from flywheel means 21 to the driving wheel 12 and prevents the energy from being transferred from driving wheel 12 back to the flywheel means 21 while the rotation speed of the driving wheel 12 is faster than that of the flywheel means 21.

With such a structure according to the present invention, as shown in FIG. 2 a, while attempting to slow down the bicycle 1, a user operates the clutching means 22 to engage the driving wheel 12 with the flywheel means 21 via the input transforming assembly 231 of the speed transforming means 23, and thereby the rotation energy of the driving wheel 12 can be transferred to the flywheel means 21 through the input transforming assembly 231 to thus slow down the moving speed of the bicycle 1 by means of reducing the rotation energy of the driving wheel 12.

As shown in FIG. 2 b, when the bicycle 1 is slowing down or is to be stopped, a user can operate the clutching means 22 to disengage the driving wheel 12 with the flywheel means 21 to thus maintain the balancing of the bicycle 1 based on the angular momentum from the rotation of the flywheel means 21 even though the driving wheel 12 and the driven wheel 13 are stopped.

As shown in FIG. 2 c, when the bicycle 1 is starting or is speeding up, a user can operate the clutching means 22 to engage the driving wheel 12 with the flywheel means 21 via the output transforming assembly 232 of the speed transforming means 23, and thereby the rotation energy of the flywheel means 21 can be transferred to the driving wheel 12 through the output transforming assembly 232 to thus enable the bicycle 1 to start up or speeding up based on the increase of the rotation energy of the driving wheel 12.

The above description should be considered as only the discussion of the preferred embodiments of the present invention. However, a person having an ordinary skill in the art may make various modifications to the present invention. Those modifications still fall within the spirit and scope defined by the appended claims 

What is claimed is:
 1. A flywheel device of a bicycle, the bicycle having a frame, a driving wheel and a driven wheel, the flywheel device comprising: a flywheel means installed on the frame that is placed between the driving wheel and the driven wheel, a rotation axis of the flywheel means being substantially parallel to a rotating axis of the driving wheel; a clutching means, engaged or disengaged between the flywheel means and the driving wheel according to an engaging state and a disengaging state thereof, wherein, a rotational energy is transferable between the flywheel means and the driving wheel during in the engaging state; and a speed transforming means connected between the flywheel means and the driving wheel by means of the clutching means to adjust a transmission ratio in relation to the driving wheel and the flywheel means.
 2. A flywheel device as claimed in claim 1, wherein the driving wheel is a rear wheel of the bicycle.
 3. A flywheel device as claimed in claim 1, wherein the flywheel means is positioned between a down tube and a seat tube of the frame.
 4. A flywheel device as claimed in claim 3, wherein the flywheel means has a flywheel edge partly extending beyond a top tube of the frame.
 5. A flywheel device as claimed in claim 1, wherein the flywheel means is rotated in connection with the driving wheel via a transmission member.
 6. A flywheel device as claimed in claim 1, wherein the clutching means is provided with a handling member for shifting the clutching means in the engaging state or the disengaging state.
 7. A flywheel device as claimed in claim 1, wherein the speed transforming means includes an input transforming assembly and an output transforming assembly, the input transforming assembly is provided to adjust an input transmission ratio of the driving wheel to the flywheel means, and the output transforming assembly is provided to adjust an output transmission ratio of the flywheel means to the driving wheel.
 8. A flywheel device as claimed in claim 7, wherein the input transmission ratio of the driving wheel to the flywheel means is adjusted as an acceleration transmission ratio by the input transforming assembly.
 9. A flywheel device as claimed in claim 7, wherein the output transmission ratio of the flywheel means to the driving wheel is adjusted as an acceleration transmission ratio by the output transforming assembly.
 10. A flywheel device as claimed in claim 1, further comprising a ratchet means assembled between the flywheel means and the driving wheel via the speed transforming means. 